DE8634288U1 - Coffee or tea machine - Google Patents

Description

Patent attorneys

Dr. Loesenbeck (198O)

DipU'rig. Stracke OipMng. Loesenbeck.

JÖlfeii&eclter Str. 164,4800 Bielefeld

Melitta Household Products GmbH & Co. KG Marienstr. 88, 4950 Minden

Coffee or tea machine

The present invention relates to a coffee or tea machine according to the generic term of patent claim 1. In a known coffee machine of the generic type (DE-GM 78 11 283), the brewing water produced by the flow heater operating according to the gravity principle is collected in the intermediate container and from there periodically fed to the filter vessel in a gush-like manner in a manner simulating manual filtration. In order to ensure that this residual water still reaches the filter vessel from the intermediate container towards the end of the brewing process, when the residual water in the intermediate container no longer reaches the level required for pressure-free operation of the siphon, an outlet opening is provided in the base of the intermediate container, which is kept closed by a float-controlled valve and which, if the control is designed appropriately, is released to drain the residual water. This design complicates the otherwise simple construction of such coffee or tea machines, takes up a lot of space and is prone to failure.

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DE-PS 12 13 968 shows a device for preparing coffee, in which a pot closed by a lid has a heater on the bottom. A siphon leads from the pot to the filter vessel. The fresh water in its entirety is brought to the boil in the pot. In the lid of the pot there is a small vent opening which allows such a strong build-up of pressure in the pot during the boiling phase that the boiling fresh water is then pressed into the filter vessel via the siphon. This would happen in a single gush, based on the total amount of fresh water. Since this is unfavourable in terms of utilization, attempts are being made to counteract this by installing a valve on the bottom of the pot under the siphon's outlet opening, which is controlled by a float in the filter vessel. This valve is intended to temporarily block the escape of the brewing water. DE-PS 12 13 968 does not deal with the expulsion of residual water from an intermediate tank in the final phase of operation of a continuous flow heater operating according to the gravity principle.

The vent hole in the lid of the pot causes hot steam to escape from the top of the device.

A coffee machine has become known from DE-AS 12 94 608 in which an intermediate container is connected upstream of the filter vessel, which is tiltable by means of a spring and is held in a controllable manner in terms of its tilting, so that it can be emptied intermittently and in a burst. This coffee machine does not have a continuous flow heater. The fresh water container is sealed except for a riser pipe that opens into the intermediate container, so that when a corresponding steam pressure is generated in the fresh water container, brewing water

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can reach the intermediate tank via the riser pipe.

According to the older application DE-OS 35 39 007 Al, a coffee or tea machine has already been proposed in which the riser pipe also leads into an intermediate container that can be periodically emptied using a siphon. There is nothing provided in the intermediate container that could cause residual water to be removed towards the end of the brewing process.

The present invention is based on the object of creating a coffee or tea machine of the generic type, which, while retaining the structure known per se for household coffee or tea machines, enables an advantageous brewing process and at the same time ensures the safe emptying of residual water quantities.

The solution according to the invention results from the characterizing part of claim 1.

By collecting the brewing water from the flow heater operating on the principle of gravity in the intermediate tank and periodically emptying it into the filter vessel using a siphon, advantageous brewing is achieved. It has been shown that towards the end of an operating phase, the steam pressure generated by the evaporation of the remaining fresh water from the flow heater is still sufficient, if the cross-section of the vent pipe in the otherwise closed intermediate tank is appropriately dimensioned, to press the remaining water in the intermediate tank through the siphon into the filter vessel. Additional design elements

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are not required. By designing the required venting device in the form of a venting pipe, one is flexible with regard to the position of the outlet opening of this pipe. As a result, the hot steam emerging from it can be advantageously assigned to the filter vessel or the fresh water tank, for example.

Further embodiments of the invention are characterized in the subclaims.

The accompanying drawings show embodiments of the invention, which are described in more detail below. They show

Fig. 1 is a schematic representation of a coffee or tea machine according to the present invention,

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Fig. 2 a coffee or tea machine according to a further embodiment of the invention.

In Figure 1, the reference numeral 10 designates a coffee or tea machine.

This coffee or tea machine 10 has the basic structure of so-called household coffee or tea machines. A predetermined amount of cold water is filled into a fresh water tank 11. This cold water is heated by a flow heater 12 and is fed via a riser pipe 13 and a pipe generally designated with the reference number 14.

provided overflow device into a filter vessel 15, which is located above a can 16 receiving the filtrate.

The pot 16 is usually placed on a hotplate" 17.

The overflow device 14 is equipped with an intermediate container 18, the special features of which are explained in more detail below.

The intermediate container 18 is equipped with a suction lifter 23, which opens into the filter vessel 15 on the outlet side.

In addition, the intermediate container 18 is provided with a vent pipe 24. This vent pipe 24 extends in the vertical direction beyond the area of the pipe bend 25 of the suction lifter 23. Otherwise, the intermediate container 18 is closed on all sides.

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The function of this construction is as follows:

First, heated water is pumped into the intermediate tank 18. If the fill level in the intermediate tank 18 is so high that the pipe bend 25 of the suction lifter 23 is filled, the suction lifter 23 comes into action and empties the intermediate tank 18 automatically.

In the event that the intermediate tank 18 cannot be completely filled during the last delivery cycle, the residual water in the intermediate tank 18 is pressed through the suction lifter 23 into the filter vessel 15 by steam pressure. The cross-section of the vent pipe 24 is expediently selected so that this vent pipe 24 cannot discharge the steam produced by the evaporation of residual water in the flow heater 12, so that, as described above, a delivery pressure is created for residual water in the intermediate tank 18.

Figure 2 shows a further embodiment of the invention with a suction lifter 23 for emptying the intermediate container 18. In this embodiment, the intermediate container 18 is arranged above the fresh water container. The riser pipe 13 flows back into this intermediate container 18. The intermediate container 18 is provided with a vent pipe 24 leading back to the fresh water container 11, which in turn ends above the pipe bend 25. ·

The outlet end of the suction lifter 23 opens into an overflow pipe 26, which leads to the filter vessel 15.

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This overflow pipe 26 is mounted in a pendulum-mounted manner and is equipped with a sealing cone 27 in the inlet area of the suction lifter 23.

The filter vessel 15 is provided in a known manner with a siphon outlet 28, which is located in an axial direction with a spring-loaded closing valve 29. This closing valve 29 is arranged on an arm 30 of the housing of the coffee or tea machine 10.

The filter vessel 15 is vertically movable in the direction of the double arrow in Figure 2.

The jug 16 which holds the filtrate is provided with a lid 31 which has a control cam 32 in its center. This control cam 32 interacts with a tappet 33 of the filter vessel 15.

The function of the coffee or tea machine shown in Figure 2 is as follows:

If the jug 16 with its lid 31 is in its intended place on the hotplate 17, the filter vessel 15 is raised vertically by the control cam 32 via the tappet 33 into the position shown in Figure 2. In this position, the suction lifter outlet 28 of the filter vessel 15 is lifted off the closing valve 29, i.e. the suction lifter outlet 28 is free. The pivoting overflow pipe 26 is also pivoted over the filter vessel 15, which is also provided with a lid 34, in such a way that the sealing cone 27 has lifted off the outlet opening of the suction lifter 23, so that

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the outlet opening of the siphon 23 is free. In this position shown in Figure 2, heated brewing water can be conveyed from the intermediate container 18 into the filter vessel 15, namely through the siphon 23 and via the overflow pipe 26.

If the vessel is now removed intentionally or due to incorrect operation, the filter vessel 15 moves downwards, the siphon outlet 28 is closed by the closing valve 29, the sealing cone 27 closes the outlet opening of the siphon 23, so that on the one hand no further hot water gets into the filter vessel 15 and on the other hand no filtrate can flow out of the filter vessel 15.

Since brewing water can continue to be pumped into the intermediate vessel 18 at the same time, as already mentioned, the vent hole 24 is led back into the fresh water tank 11, i.e. excess heated water can flow back into the fresh water tank 11 via the vent hole 24.

Claims (4)

Melitta - 9 - Protection claims 1. Coffee or tea machine with a fresh water tank, a flow heater operating according to the principle of gravity, a riser pipe and an overflow device for introducing the heated water into a filter vessel arranged above a jug for receiving the filtrate, the riser pipe opening into an intermediate container which can be periodically emptied by means of a siphon and forms part of the overflow device, characterized in that the intermediate container (18) is provided with a vent pipe (24) and is otherwise closed on all sides and the vent pipe (24) has such a small cross-section that the vent pipe (24) prevents the excess pressure which arises within the intermediate container (18) when residual water quantities in the flow heater (12) evaporate from being reduced by the vent pipe (24). 2. Coffee or tea machine according to claim 1, characterized in that the vent pipe (24) extends over the pipe bend (25) of the suction lifter (23) extends upwards. 3. Coffee or tea machine according to claim 1 or 2, characterized in that the outlet area of the suction lifter (23) is pivotably mounted and with a pivoting end position which closes the outlet of the suction lifter (23) closing the overflow pipe (26) with a sealing cone (27). 4. Coffee or tea machine according to one or more of the preceding claims, characterized in that the ventilation pipe (24) opens into the fresh water container (11) on the outlet side.